Infiniti President and CEO Johan de Nysschen unveiled the Nissan luxury brand's bread-and-butter Q50 sport sedan at the 2013 New York International Auto Show, with its usual 3.7-L V6 engine carried over from its previous life as the G37 and a new hybrid electric drivetrain.
While Nissan and Infiniti are renowned for the quality of the VQ V6 engine family, fuel economy concerns brought the spotlight to the company's new hybrid drivetrains. For the sport-minded Q50, that means an electric motor-backed V6 for maximum power. For the family-focused QX60, and its Nissan Pathfinder sibling, that means a fuel-saving 2.5-L four-cylinder engine with a smaller electric assist motor.
The Q50 will feature a 328-hp (245-kW), 269-lb·ft (365-N·m) 3.7-L V6 engine, with the hybrid positioned as the performance option. It includes a 296-hp (221-kW), 255-lb·ft (346-N·m) 3.5-L DOHC V6 gasoline engine matched with a 50-kW, 199-lb·ft (270-N·m) electric motor for a total system peak power of 354 hp (264 kW). The transmission for either engine is a seven-speed automatic.
A four-cylinder gasoline engine will be announced for world markets, but a diesel option is not planned for the near future, de Nysschen said. That's because the company is primarily targeting markets that prefer gasoline—the U.S., Japan, and China—and because this performance hybrid is tuned to deliver diesel-like performance and efficiency, he explained. "With the hybrid, looking at the incremental volume (a diesel) would add is very small," de Nysschen said. "We have to avoid the trap of offering one customer two cars."
As a small brand with limited resources, nice-to-have options such as diesel power will have to wait, though it is an eventual goal for Infiniti to have diesel engines, he said.
The electric motor is sandwiched between the gasoline engine and the automatic transmission, isolated with a pair of clutches that let it connect to assist the gas motor or to power the car and regenerate energy during deceleration decoupled from the gasoline engine.
The Q50 Hybrid will be available in both rear- and all-wheel-drive configurations this summer, beginning in U.S. and Canadian markets. Starting at $43,700, the hybrid is priced $4400 above the comparable gasoline model.
The QX50 and Nissan Pathfinder use similar building blocks to construct a fuel-saving powertrain for the bigger, heavier crossover SUV family haulers. In their case, gasoline power is from a supercharged 230-hp (172-kW), 2.5-L DOHC I4 connected to a 15-kW electric motor for a total system power of 250 hp (186 kW) and 243 lb·ft (329 N·m) with a 24% boost in fuel efficiency.
As with their gasoline-powered versions, the hybrid SUVs use a continuously variable transmission, with the electric motor packaged between the gasoline motor and the CVT in place of the torque converter.
The resulting EPA fuel economy is 25 mpg city and 27 mpg highway, with an estimated driving range of 526 mi (847 km).
The downsized gasoline engine in this application is supercharged to provide the kind of instant torque that a heavy vehicle like the QX/Pathfinder demands, especially if it is towing. It uses an Eaton twin vortex technology supercharger. With the optional tow package, this hybrid is rated to tow 3500 lb (1590 kg).
While many gasoline engines in hybrid-electric vehicles use Atkinson (rather than Otto) cycle combustion, Product Planner Adam O'Shaughnessy said that is not the case here. However, he did say that the engine's combustion is unconventional and that the company will soon discuss details of this. Considering the forced induction, a variation of Miller cycle combustion seems possible.
The small lithium-ion battery pack fits under the floor beneath the third-row seat in the QX/Pathfinder, imposing no reduction in cargo space or flexibility, which is unusual for a hybrid model.
Another unusual aspect of these hybrids is their relatively small price premium over the gasoline models. In this case, each of them costs only $3000 more than their thirstier siblings. They are available in both two- and four-wheel-drive versions that should arrive in dealers near the end of the year.